[sage-support] Re: parametric plot bug? and text plotting "feature"
On Mon, 07 Apr 2008 at 08:10PM -0700, kcrisman wrote: > Final comment - are both related to > sage: parametric_plot((0,t),0,1) > not working, which is consistent with > sage: plot(1) > not returning a horizontal line, but (sort of) inconsistent with > sage: plot(sin) > returning a curve, since Integer(1) is not callable symbolically? > Sorry for the self-responses, just trying to clarify in case there > really is something here worth looking at. I think I've run into this problem before, where constants cannot be coerced into functions. I really wish that worked; when I type plot(2, x, -1, 1) I *don't* want to see the numeral "2" printed at the origin, and I can't imagine anybody who would. Dan -- --- Dan Drake <[EMAIL PROTECTED]> - KAIST Department of Mathematical Sciences --- http://math.kaist.ac.kr/~drake signature.asc Description: Digital signature
[sage-support] Re: parametric plot bug? and text plotting "feature"
Final comment - are both related to sage: parametric_plot((0,t),0,1) not working, which is consistent with sage: plot(1) not returning a horizontal line, but (sort of) inconsistent with sage: plot(sin) returning a curve, since Integer(1) is not callable symbolically? Sorry for the self-responses, just trying to clarify in case there really is something here worth looking at. - kcrisman --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: parametric plot bug? and text plotting "feature"
To follow up, I should point out the problem seems to be in parametric_plot and the pure imaginary points like exp(i*pi/2) specifically, as sage: parametric_plot( (real(x*exp(i*pi/2)),imag(x*exp(i*pi/2))),0,10) causes the same problem, even though sage: [(float(real(x*exp(i*pi/2))),float(imag(x*exp(i*pi/2 for x in [0..10]] [(0.0, 0.0), (0.0, 1.0), (0.0, 2.0), (0.0, 3.0), (0.0, 4.0), (0.0, 5.0), (0.0, 6.0), (0.0, 7.0), (0.0, 8.0), (0.0, 9.0), (0.0, 10.0)] Sorry if the first example obscures anything. --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] parametric plot bug? and text plotting "feature"
In notebook on sagemath.org, the strange behavior reported at the end
of this post occurs with parametric plots. It isn't clear to me
whether this is some mistake of mine in trying to plot complex
parametric curves, or a bug in plot related to previous subscripting
issues. Using C(pi/5,r) instead of C(pi/5) produced the same
results. I hope this is useful.
By the way, if there is any better way to do complex parametric plots
I would appreciate hearing about it; somehow I feel like there must be
a way for plot to recognize complex points, but experimentation and
perusing the docs/code make me feel that it's only reals for now. On
a related note, check out the results of
sage: plot((0,1)) (or plot([0,1]) , but not plot(0,1) )
and
sage: plot(25)
- very interesting, which somehow I find a feature, not a bug, but of
course a hard feature to use effectively! I get the same thing with
sage: text(0,(-1,1))+text(1,(-1,1))
and
text(25,(0,0))
of course.
- kcrisman
sage: var('z,t,r')
(z, t, r)
sage: a=1+i
sage: C(theta,r)=r*exp(i*theta)
sage: P=parametric_plot( (real(a*C(pi/5)),imag(a*C(pi/5)) ), 0, 5);
show(P) [This shows up fine.]
sage: Q=parametric_plot( (real(a*C(pi/4)),imag(a*C(pi/4)) ), 0, 5);
show(Q)
verbose 0 (3576: plot.py, _call) WARNING: When plotting, failed to
evaluate function at 200 points.
verbose 0 (3576: plot.py, _call) Last error message: 'the number of
arguments must be less than or equal to 0'
Traceback (most recent call last):
File "", line 1, in
File "/home/server2/sage_notebook/worksheets/kcrisman/5/code/5.py",
line 6, in
exec compile(ur'Q=parametric_plot( (real(a*C(pi/
Integer(4))),imag(a*C(pi/Integer(4))) ), Integer(0), Integer(5));
show(Q)' + '\n', '', 'single')
File "/usr/local/sage/local/lib/python2.5/site-packages/sympy/
plotting/", line 1, in
File "/usr/local/sage/local/lib/python2.5/site-packages/sage/plot/
plot.py", line 3773, in parametric_plot
return plot(funcs, tmin, tmax, parametric=True,
**kwargs)
File "/usr/local/sage/local/lib/python2.5/site-packages/sage/plot/
plot.py", line 3569, in __call__
G = self._call(funcs, (xmin, xmax), *args, **kwds)
File "/usr/local/sage/local/lib/python2.5/site-packages/sage/plot/
plot.py", line 3668, in _call
G = line(data, coerce=False, **options)
File "/usr/local/sage/local/lib/python2.5/site-packages/sage/plot/
plot.py", line 2680, in __call__
isinstance(points[0], (list,tuple))):
IndexError: list index out of range
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[sage-support] Re: Sage search engine?
Well, I didn't write that javascript part, but I can tell you that if you click the link to add the search engine to your browser, you could save a few more clicks. BTW, the page doesn't actually install anything into your browser, it just triggers the function in your browser that lets _you_ add the search engine. On Apr 7, 6:28 pm, Michael <[EMAIL PROTECTED]> wrote: > The search engine at the bottom ofhttp://www.sagemath.org/documentation.html > has stopped working for me in IE, Firefox, and Opera. > > When I type something into the search box, the results appear but only > in the tiny little window at the bottom of the page so I cannot see > the results unless I scroll through the little window (by using the > arrow keys or by tabbing). If I click on the Sage Search Engine link, > then I get a full page and can see the results after typing a query. > > I believe that the box at the bottom of the page used to work (thus > saving me a click). > > Was this change intended? --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Sage search engine?
I have used the following as a fudge: http://www.google.com/search?hl=en&lr=&as_qdr=all&q=+site%3Ahttp%3A%2F%2Fsagemath.org&btnG=Search Dean --- On Mon, Apr 7, 2008 at 5:28 PM, Michael <[EMAIL PROTECTED]> wrote: > > The search engine at the bottom of > http://www.sagemath.org/documentation.html > has stopped working for me in IE, Firefox, and Opera. > > When I type something into the search box, the results appear but only > in the tiny little window at the bottom of the page so I cannot see > the results unless I scroll through the little window (by using the > arrow keys or by tabbing). If I click on the Sage Search Engine link, > then I get a full page and can see the results after typing a query. > > I believe that the box at the bottom of the page used to work (thus > saving me a click). > > Was this change intended? > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Sage search engine?
The search engine at the bottom of http://www.sagemath.org/documentation.html has stopped working for me in IE, Firefox, and Opera. When I type something into the search box, the results appear but only in the tiny little window at the bottom of the page so I cannot see the results unless I scroll through the little window (by using the arrow keys or by tabbing). If I click on the Sage Search Engine link, then I get a full page and can see the results after typing a query. I believe that the box at the bottom of the page used to work (thus saving me a click). Was this change intended? --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: pylab inside notebook
See https://www.sagenb.org/home/pub/1463/
from pylab import *
plot([1,2,3,4])
savefig('foo.png')
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[sage-support] Re: GeneratorsOfGroup
Hi Becky, Did you have a particular group in mind? --Mike On Mon, Apr 7, 2008 at 3:19 PM, Becky <[EMAIL PROTECTED]> wrote: > > Is there a command for SAGE to write an element of a group in terms of > the group's generators? > -Becky > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] GeneratorsOfGroup
Is there a command for SAGE to write an element of a group in terms of the group's generators? -Becky --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: code to find roots no longer works
Dear Mike, Thank you very much for your explanation and solution. The amended code now works perfectly. You made my day! Best regards, John Mike Hansen wrote: > Hi, > > The issue is that .roots() now returns tuples with the root and its > multiplicity. You can see this if you look at v. You need to select > the 0th entry of the tuple to raise to a power. > > sage: RDF = RealDoubleField() > sage: R. = PolynomialRing(RDF) > sage: # Let y be x^(1/9). > sage: f = y + RDF(2^(8/9) - 2^(1/9))*(y^9-1) - y^8 > sage: v = f.roots(); v > [(0.925874712287, 1), (1.0, 1), (1.08005973889, 1)] > sage: [a[0]^9 for a in v] > [0.5, 1.0, 2.0] > > --Mike > > > On Mon, Apr 7, 2008 at 2:06 PM, John P. Burkett <[EMAIL PROTECTED]> wrote: >> Last September I asked how to use SAGE to find the roots of >> f = x^(1/9) + (2^(8/9) - 2^(1/9))*(x - 1) - x^(8/9). >> William Stein then kindly offered the following code: >> sage: RDF = RealDoubleField() >> sage: R. = PolynomialRing(RDF) >> sage: # Let y be x^(1/9). >> sage: f = y + RDF(2^(8/9) - 2^(1/9))*(y^9-1) - y^8 >> sage: v = f.roots(); v >> sage: [a^9 for a in v] >> >> This code worked well on my machines when I first tried it. However, >> today in SAGE 2.11 the same code running on the same machines produces >> the following error message: >> >> Traceback (most recent call last) >> >> /home/john/ in () >> >> /home/john/integer.pyx in sage.rings.integer.Integer.__pow__() >> >> : unsupported operand type(s) for ** or >> pow(): 'tuple' and 'int' >> >> I would be very grateful for ideas about what has gone wrong and how to >> fix it. >> >> Best regards, >> John >> -- >> John P. Burkett >> Department of Environmental and Natural Resource Economics >> and Department of Economics >> University of Rhode Island >> Kingston, RI 02881-0808 >> USA >> >> phone (401) 874-9195 >> >> > >> > > > > -- John P. Burkett Department of Environmental and Natural Resource Economics and Department of Economics University of Rhode Island Kingston, RI 02881-0808 USA phone (401) 874-9195 --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: code to find roots no longer works
Hi, The issue is that .roots() now returns tuples with the root and its multiplicity. You can see this if you look at v. You need to select the 0th entry of the tuple to raise to a power. sage: RDF = RealDoubleField() sage: R. = PolynomialRing(RDF) sage: # Let y be x^(1/9). sage: f = y + RDF(2^(8/9) - 2^(1/9))*(y^9-1) - y^8 sage: v = f.roots(); v [(0.925874712287, 1), (1.0, 1), (1.08005973889, 1)] sage: [a[0]^9 for a in v] [0.5, 1.0, 2.0] --Mike On Mon, Apr 7, 2008 at 2:06 PM, John P. Burkett <[EMAIL PROTECTED]> wrote: > > Last September I asked how to use SAGE to find the roots of > f = x^(1/9) + (2^(8/9) - 2^(1/9))*(x - 1) - x^(8/9). > William Stein then kindly offered the following code: > sage: RDF = RealDoubleField() > sage: R. = PolynomialRing(RDF) > sage: # Let y be x^(1/9). > sage: f = y + RDF(2^(8/9) - 2^(1/9))*(y^9-1) - y^8 > sage: v = f.roots(); v > sage: [a^9 for a in v] > > This code worked well on my machines when I first tried it. However, > today in SAGE 2.11 the same code running on the same machines produces > the following error message: > > Traceback (most recent call last) > > /home/john/ in () > > /home/john/integer.pyx in sage.rings.integer.Integer.__pow__() > > : unsupported operand type(s) for ** or > pow(): 'tuple' and 'int' > > I would be very grateful for ideas about what has gone wrong and how to > fix it. > > Best regards, > John > -- > John P. Burkett > Department of Environmental and Natural Resource Economics > and Department of Economics > University of Rhode Island > Kingston, RI 02881-0808 > USA > > phone (401) 874-9195 > > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] code to find roots no longer works
Last September I asked how to use SAGE to find the roots of f = x^(1/9) + (2^(8/9) - 2^(1/9))*(x - 1) - x^(8/9). William Stein then kindly offered the following code: sage: RDF = RealDoubleField() sage: R. = PolynomialRing(RDF) sage: # Let y be x^(1/9). sage: f = y + RDF(2^(8/9) - 2^(1/9))*(y^9-1) - y^8 sage: v = f.roots(); v sage: [a^9 for a in v] This code worked well on my machines when I first tried it. However, today in SAGE 2.11 the same code running on the same machines produces the following error message: Traceback (most recent call last) /home/john/ in () /home/john/integer.pyx in sage.rings.integer.Integer.__pow__() : unsupported operand type(s) for ** or pow(): 'tuple' and 'int' I would be very grateful for ideas about what has gone wrong and how to fix it. Best regards, John -- John P. Burkett Department of Environmental and Natural Resource Economics and Department of Economics University of Rhode Island Kingston, RI 02881-0808 USA phone (401) 874-9195 --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Fwd: elliptic curve trace problem in SAGE
I have posted a patch for this on trac #2849. The bug would strike for any curve with j=0 (=1728) defined over GF(3^d) for odd d. Assuming someone reviews this positively it will get into sage-3.0. It is also likely that by then there will be much better support for the cases j=0 and j=1728 anyway. John Cremona On 07/04/2008, William Stein <[EMAIL PROTECTED]> wrote: > > An elliptic curve bug report from a student of Koblitz... > > > -- Forwarded message -- > From: <[EMAIL PROTECTED]> > Date: Mon, Apr 7, 2008 at 12:39 PM > Subject: elliptic curve trace problem in SAGE > To: [EMAIL PROTECTED] > > > William, > While working on some things, I found a bug in SAGE: > > sage:k.=GF(3^5) > > sage:E=EllipticCurve(k,[-1,-1]) > > sage:E.trace_of_frobenius() > 0 > > This isn't correct. It should be -27. I also discovered you can get > around it. > > sage:E.cardinality_exhaustive() > 271 > > sage:E.trace_of_frobenius() > -27 > > Somehow, doing .cardinality_exhaustive() fixes the bug. > > > > Dustin Moody > > > > > > > > -- > William Stein > Associate Professor of Mathematics > University of Washington > http://wstein.org > > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Fwd: elliptic curve trace problem in SAGE
I'll fix this as it is my code. Note that this curve has j=0 and the cases of j=0, 1728 were not implemented with any efficiency (or, it seems correctness), but that I am half-way through doing that. In the meantime I'll try to put in a quick patch to correct what's wrong here. First step, I'll open a ticket. John Cremona On 07/04/2008, William Stein <[EMAIL PROTECTED]> wrote: > > An elliptic curve bug report from a student of Koblitz... > > > -- Forwarded message -- > From: <[EMAIL PROTECTED]> > Date: Mon, Apr 7, 2008 at 12:39 PM > Subject: elliptic curve trace problem in SAGE > To: [EMAIL PROTECTED] > > > William, > While working on some things, I found a bug in SAGE: > > sage:k.=GF(3^5) > > sage:E=EllipticCurve(k,[-1,-1]) > > sage:E.trace_of_frobenius() > 0 > > This isn't correct. It should be -27. I also discovered you can get > around it. > > sage:E.cardinality_exhaustive() > 271 > > sage:E.trace_of_frobenius() > -27 > > Somehow, doing .cardinality_exhaustive() fixes the bug. > > > > Dustin Moody > > > > > > > > -- > William Stein > Associate Professor of Mathematics > University of Washington > http://wstein.org > > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
Yes, see here: http://www.fenics.org/wiki/Download -- Anders On 7 Apr, 20:48, "David Joyner" <[EMAIL PROTECTED]> wrote: > On Mon, Apr 7, 2008 at 2:35 PM, Anders Logg <[EMAIL PROTECTED]> wrote: > > > On 7 Apr, 16:47, "Ondrej Certik" <[EMAIL PROTECTED]> wrote: > > > On Mon, Apr 7, 2008 at 4:15 PM, David Joyner <[EMAIL PROTECTED]> wrote: > > > > > On Mon, Apr 7, 2008 at 10:08 AM, Ondrej Certik <[EMAIL PROTECTED]> > > wrote: > > > > > > On Mon, Apr 7, 2008 at 3:41 PM, Mike Hansen <[EMAIL PROTECTED]> > > wrote: > > > > > > > On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL > > PROTECTED]> wrote: > > > > > > > Yes, I did. This is the code developed by people at Simula. > > It works > > > > > > > nice, but it's quite difficult to install. I generally > > prefer smaller > > > > > > > tools, if I can get the job done. > > > > > > > > Ondrej > > > > > > > Other than size and build issues, are the two projects > > equivalent > > > > > > feature / speed-wise? > > > > > > To my purposes, sfepy is better than fenics, because sfepy is in > > > > > python (and can do all I need). As to speed, that's about the same, > > > > > because the mainloop of sfepy for the assembly is in pure C, > > without > > > > > any python callbacks. Also because it's smaller, I find it simpler > > to > > > > > use. But Fenics definitely is also good and have it's users. > > > > > Feature-wise, is Fenics better than sfepy? > > > > I tried Fenics about a year ago, so they may have improved. For my own > > > purposes, i.e. solving a PDE, with Neumann or Dirichlet boundary > > > conditions, > > > assigning different material properties to different regions in the > > > body, etc., sfepy is better in a sense, that I was able to do what I > > > want in it (with the help of Robert) easier than in Fenics. > > > > > You did seem to indicate sfepy > > > > is smaller. Is it because Fenics does more? > > > > Because they are doing almost everything in C++, while sfepy uses a > > > very clever approach of only doing the main assembly loop in pure C, > > > otherwise doing everything in Python (so it's the same fast as the > > > libmesh (also C++ library) for my own purposes). Also, at the time I > > > tried Fenics, I had to code in C++ to do what I want. I don't like > > > that, I prefer > > > to work in Python (in sfepy, you don't have to touch the C code, > > > unless you want to do something very unusual). But they may have > > > improved since then. > > > > > Also, isn't Fenics also in > > > > C+Python? > > > > It's Python + C++. I don't like C++, I really prefer Python + C, it's > > > easier to understand, cleaner, more portable, easier to wrap in > > > Python, etc. > > > > Well, download the sources of Dolfin and sfepy and see for yourself. > > > It takes less than 30s to compile sfepy on my computer. I haven't > > > tried dolphin, because it requires some dependencies I don't have, but > > > I am sure it will take at least 20x more time. Sfepy only requires > > > numpy+scipy. > > > > Ondrej > > > Just a few comments. > > > 1. Yes, we have improved (as always... :-) but it's still far from > > finished. > > > There's a simple example demonstrating the solution of Poisson's > > equation > > on this page:http://www.fenics.org/wiki/Tutorial > > > More demos can be found here: > > > http://www.fenics.org/hg/dolfin?cmd=manifest;manifest=e91acc1d9b39276... > > > 2. Yes, FEniCS is fairly complex:http://www.fenics.org/wiki/Projects > > > However, this shouldn't be a problem for users, and there are (Ubuntu) > > packages > > that let you install everything by just doing apt-get install fenics. > > [EMAIL PROTECTED]:~/wdj/computer_algebra/dolfin$ sudo apt-get install fenics > [sudo] password for wdj: > Reading package lists... Done > Building dependency tree > Reading state information... Done > E: Couldn't find package fenics > > Maybe a site has to be added to /etc/sources? > > > > > -- > > Anders --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Fwd: elliptic curve trace problem in SAGE
An elliptic curve bug report from a student of Koblitz... -- Forwarded message -- From: <[EMAIL PROTECTED]> Date: Mon, Apr 7, 2008 at 12:39 PM Subject: elliptic curve trace problem in SAGE To: [EMAIL PROTECTED] William, While working on some things, I found a bug in SAGE: sage:k.=GF(3^5) sage:E=EllipticCurve(k,[-1,-1]) sage:E.trace_of_frobenius() 0 This isn't correct. It should be -27. I also discovered you can get around it. sage:E.cardinality_exhaustive() 271 sage:E.trace_of_frobenius() -27 Somehow, doing .cardinality_exhaustive() fixes the bug. Dustin Moody -- William Stein Associate Professor of Mathematics University of Washington http://wstein.org --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On Mon, Apr 7, 2008 at 2:35 PM, Anders Logg <[EMAIL PROTECTED]> wrote: > > On 7 Apr, 16:47, "Ondrej Certik" <[EMAIL PROTECTED]> wrote: > > On Mon, Apr 7, 2008 at 4:15 PM, David Joyner <[EMAIL PROTECTED]> wrote: > > > > > On Mon, Apr 7, 2008 at 10:08 AM, Ondrej Certik <[EMAIL PROTECTED]> > wrote: > > > > > > On Mon, Apr 7, 2008 at 3:41 PM, Mike Hansen <[EMAIL PROTECTED]> > wrote: > > > > > > > > > On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL PROTECTED]> > wrote: > > > > > > Yes, I did. This is the code developed by people at Simula. It > works > > > > > > nice, but it's quite difficult to install. I generally prefer > smaller > > > > > > tools, if I can get the job done. > > > > > > > > Ondrej > > > > > > > Other than size and build issues, are the two projects equivalent > > > > > feature / speed-wise? > > > > > > To my purposes, sfepy is better than fenics, because sfepy is in > > > > python (and can do all I need). As to speed, that's about the same, > > > > because the mainloop of sfepy for the assembly is in pure C, without > > > > any python callbacks. Also because it's smaller, I find it simpler to > > > > use. But Fenics definitely is also good and have it's users. > > > > > Feature-wise, is Fenics better than sfepy? > > > > I tried Fenics about a year ago, so they may have improved. For my own > > purposes, i.e. solving a PDE, with Neumann or Dirichlet boundary > > conditions, > > assigning different material properties to different regions in the > > body, etc., sfepy is better in a sense, that I was able to do what I > > want in it (with the help of Robert) easier than in Fenics. > > > > > You did seem to indicate sfepy > > > is smaller. Is it because Fenics does more? > > > > Because they are doing almost everything in C++, while sfepy uses a > > very clever approach of only doing the main assembly loop in pure C, > > otherwise doing everything in Python (so it's the same fast as the > > libmesh (also C++ library) for my own purposes). Also, at the time I > > tried Fenics, I had to code in C++ to do what I want. I don't like > > that, I prefer > > to work in Python (in sfepy, you don't have to touch the C code, > > unless you want to do something very unusual). But they may have > > improved since then. > > > > > Also, isn't Fenics also in > > > C+Python? > > > > It's Python + C++. I don't like C++, I really prefer Python + C, it's > > easier to understand, cleaner, more portable, easier to wrap in > > Python, etc. > > > > Well, download the sources of Dolfin and sfepy and see for yourself. > > It takes less than 30s to compile sfepy on my computer. I haven't > > tried dolphin, because it requires some dependencies I don't have, but > > I am sure it will take at least 20x more time. Sfepy only requires > > numpy+scipy. > > > > Ondrej > > Just a few comments. > > 1. Yes, we have improved (as always... :-) but it's still far from > finished. > > There's a simple example demonstrating the solution of Poisson's > equation > on this page: http://www.fenics.org/wiki/Tutorial > > More demos can be found here: > > > http://www.fenics.org/hg/dolfin?cmd=manifest;manifest=e91acc1d9b392762c6cc1310abad399aef240993;path=/demo/ > > 2. Yes, FEniCS is fairly complex: http://www.fenics.org/wiki/Projects > > However, this shouldn't be a problem for users, and there are (Ubuntu) > packages > that let you install everything by just doing apt-get install fenics. [EMAIL PROTECTED]:~/wdj/computer_algebra/dolfin$ sudo apt-get install fenics [sudo] password for wdj: Reading package lists... Done Building dependency tree Reading state information... Done E: Couldn't find package fenics Maybe a site has to be added to /etc/sources? > > -- > Anders > > > > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On 7 Apr, 16:47, "Ondrej Certik" <[EMAIL PROTECTED]> wrote: > On Mon, Apr 7, 2008 at 4:15 PM, David Joyner <[EMAIL PROTECTED]> wrote: > > > On Mon, Apr 7, 2008 at 10:08 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > > > > On Mon, Apr 7, 2008 at 3:41 PM, Mike Hansen <[EMAIL PROTECTED]> wrote: > > > > > On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL PROTECTED]> > > wrote: > > > > > Yes, I did. This is the code developed by people at Simula. It > > works > > > > > nice, but it's quite difficult to install. I generally prefer > > smaller > > > > > tools, if I can get the job done. > > > > > > Ondrej > > > > > Other than size and build issues, are the two projects equivalent > > > > feature / speed-wise? > > > > To my purposes, sfepy is better than fenics, because sfepy is in > > > python (and can do all I need). As to speed, that's about the same, > > > because the mainloop of sfepy for the assembly is in pure C, without > > > any python callbacks. Also because it's smaller, I find it simpler to > > > use. But Fenics definitely is also good and have it's users. > > > Feature-wise, is Fenics better than sfepy? > > I tried Fenics about a year ago, so they may have improved. For my own > purposes, i.e. solving a PDE, with Neumann or Dirichlet boundary > conditions, > assigning different material properties to different regions in the > body, etc., sfepy is better in a sense, that I was able to do what I > want in it (with the help of Robert) easier than in Fenics. > > > You did seem to indicate sfepy > > is smaller. Is it because Fenics does more? > > Because they are doing almost everything in C++, while sfepy uses a > very clever approach of only doing the main assembly loop in pure C, > otherwise doing everything in Python (so it's the same fast as the > libmesh (also C++ library) for my own purposes). Also, at the time I > tried Fenics, I had to code in C++ to do what I want. I don't like > that, I prefer > to work in Python (in sfepy, you don't have to touch the C code, > unless you want to do something very unusual). But they may have > improved since then. > > > Also, isn't Fenics also in > > C+Python? > > It's Python + C++. I don't like C++, I really prefer Python + C, it's > easier to understand, cleaner, more portable, easier to wrap in > Python, etc. > > Well, download the sources of Dolfin and sfepy and see for yourself. > It takes less than 30s to compile sfepy on my computer. I haven't > tried dolphin, because it requires some dependencies I don't have, but > I am sure it will take at least 20x more time. Sfepy only requires > numpy+scipy. > > Ondrej Just a few comments. 1. Yes, we have improved (as always... :-) but it's still far from finished. There's a simple example demonstrating the solution of Poisson's equation on this page: http://www.fenics.org/wiki/Tutorial More demos can be found here: http://www.fenics.org/hg/dolfin?cmd=manifest;manifest=e91acc1d9b392762c6cc1310abad399aef240993;path=/demo/ 2. Yes, FEniCS is fairly complex: http://www.fenics.org/wiki/Projects However, this shouldn't be a problem for users, and there are (Ubuntu) packages that let you install everything by just doing apt-get install fenics. -- Anders --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On Mon, Apr 7, 2008 at 4:15 PM, David Joyner <[EMAIL PROTECTED]> wrote: > > > On Mon, Apr 7, 2008 at 10:08 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > > > > On Mon, Apr 7, 2008 at 3:41 PM, Mike Hansen <[EMAIL PROTECTED]> wrote: > > > > > > On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL PROTECTED]> > wrote: > > > > Yes, I did. This is the code developed by people at Simula. It works > > > > nice, but it's quite difficult to install. I generally prefer > smaller > > > > tools, if I can get the job done. > > > > > > > > Ondrej > > > > > > Other than size and build issues, are the two projects equivalent > > > feature / speed-wise? > > > > To my purposes, sfepy is better than fenics, because sfepy is in > > python (and can do all I need). As to speed, that's about the same, > > because the mainloop of sfepy for the assembly is in pure C, without > > any python callbacks. Also because it's smaller, I find it simpler to > > use. But Fenics definitely is also good and have it's users. > > > Feature-wise, is Fenics better than sfepy? I tried Fenics about a year ago, so they may have improved. For my own purposes, i.e. solving a PDE, with Neumann or Dirichlet boundary conditions, assigning different material properties to different regions in the body, etc., sfepy is better in a sense, that I was able to do what I want in it (with the help of Robert) easier than in Fenics. > You did seem to indicate sfepy > is smaller. Is it because Fenics does more? Because they are doing almost everything in C++, while sfepy uses a very clever approach of only doing the main assembly loop in pure C, otherwise doing everything in Python (so it's the same fast as the libmesh (also C++ library) for my own purposes). Also, at the time I tried Fenics, I had to code in C++ to do what I want. I don't like that, I prefer to work in Python (in sfepy, you don't have to touch the C code, unless you want to do something very unusual). But they may have improved since then. > Also, isn't Fenics also in > C+Python? It's Python + C++. I don't like C++, I really prefer Python + C, it's easier to understand, cleaner, more portable, easier to wrap in Python, etc. Well, download the sources of Dolfin and sfepy and see for yourself. It takes less than 30s to compile sfepy on my computer. I haven't tried dolphin, because it requires some dependencies I don't have, but I am sure it will take at least 20x more time. Sfepy only requires numpy+scipy. Ondrej --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On Mon, Apr 7, 2008 at 10:08 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > > On Mon, Apr 7, 2008 at 3:41 PM, Mike Hansen <[EMAIL PROTECTED]> wrote: > > > > On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > > > Yes, I did. This is the code developed by people at Simula. It works > > > nice, but it's quite difficult to install. I generally prefer smaller > > > tools, if I can get the job done. > > > > > > Ondrej > > > > Other than size and build issues, are the two projects equivalent > > feature / speed-wise? > > To my purposes, sfepy is better than fenics, because sfepy is in > python (and can do all I need). As to speed, that's about the same, > because the mainloop of sfepy for the assembly is in pure C, without > any python callbacks. Also because it's smaller, I find it simpler to > use. But Fenics definitely is also good and have it's users. Feature-wise, is Fenics better than sfepy? You did seem to indicate sfepy is smaller. Is it because Fenics does more? Also, isn't Fenics also in C+Python? > > Ondrej > > > > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On Mon, Apr 7, 2008 at 3:41 PM, Mike Hansen <[EMAIL PROTECTED]> wrote: > > On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > > Yes, I did. This is the code developed by people at Simula. It works > > nice, but it's quite difficult to install. I generally prefer smaller > > tools, if I can get the job done. > > > > Ondrej > > Other than size and build issues, are the two projects equivalent > feature / speed-wise? To my purposes, sfepy is better than fenics, because sfepy is in python (and can do all I need). As to speed, that's about the same, because the mainloop of sfepy for the assembly is in pure C, without any python callbacks. Also because it's smaller, I find it simpler to use. But Fenics definitely is also good and have it's users. Ondrej --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On Mon, Apr 7, 2008 at 6:25 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > Yes, I did. This is the code developed by people at Simula. It works > nice, but it's quite difficult to install. I generally prefer smaller > tools, if I can get the job done. > > Ondrej Other than size and build issues, are the two projects equivalent feature / speed-wise? --Mike --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: [sage-devel] Re: [sage-support] PDE and Finite Element methods
On Mon, Apr 7, 2008 at 3:12 PM, David Joyner <[EMAIL PROTECTED]> wrote: > > Hector told me (in a separate email) about DOLFIN > http://www.fenics.org/wiki/FEniCS_Project > which is built on numpy. Although I had trouble installing it, > I'm wondering if anyone else on this list has been able to try it out? Yes, I did. This is the code developed by people at Simula. It works nice, but it's quite difficult to install. I generally prefer smaller tools, if I can get the job done. Ondrej --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: PDE and Finite Element methods
Hector told me (in a separate email) about DOLFIN http://www.fenics.org/wiki/FEniCS_Project which is built on numpy. Although I had trouble installing it, I'm wondering if anyone else on this list has been able to try it out? Cross-posting to sage-devel. On Wed, Apr 2, 2008 at 7:19 PM, Hector Villafuerte <[EMAIL PROTECTED]> wrote: > > Hi, > I wonder what the current situation in SAGE is for dealing with PDE > and methods to solve them numerically, such as say Finite Elements. > > A quick search threw this thread (which I'm afraid is not very conclusive): > > http://groups.google.com/group/sage-devel/browse_thread/thread/15c7e426fc571e26 > > Thanks in advance for any pointers! > -- > Hector > > > > --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Fwd: [sage-support] Re: PDE and Finite Element methods
Forwarding Robert's answer, he had some problems with sending the email. -- Forwarded message -- From: Robert Cimrman <> Date: Mon, Apr 7, 2008 at 1:51 PM Subject: Re: [sage-support] Re: PDE and Finite Element methods To: Ondrej Certik <> Cc: sage-support@googlegroups.com Ondrej Certik wrote: > On Fri, Apr 4, 2008 at 6:27 PM, William Stein <[EMAIL PROTECTED]> wrote: > > > > > On Thu, Apr 3, 2008 at 9:53 AM, Ondrej Certik <[EMAIL PROTECTED]> wrote: > > > > > > On Thu, Apr 3, 2008 at 2:18 AM, William Stein <[EMAIL PROTECTED]> wrote: > > > > > > > > On Wed, Apr 2, 2008 at 4:19 PM, Hector Villafuerte <[EMAIL > > PROTECTED]> wrote: > > > > > > > > > > Hi, > > > > > I wonder what the current situation in SAGE is for dealing with > > PDE > > > > > and methods to solve them numerically, such as say Finite > > Elements. > > > > > > > > > > A quick search threw this thread (which I'm afraid is not very > > conclusive): > > > > > > > http://groups.google.com/group/sage-devel/browse_thread/thread/15c7e426fc571e26 > > > > > > > > > > Thanks in advance for any pointers! > > > > > > > > I don't know, since that's not my area. However, it would be a > > > > really good idea > > > > to ask this same question on the scipy list (maybe this one)?: > > > >http://projects.scipy.org/mailman/listinfo/scipy-dev > > > > > > > > Also do a google search for > > > > pde finite element scipy > > > > This paper that pops up might be relevant: > > > >http://ieeexplore.ieee.org/iel5/5992/4160244/04160257.pdf > > > > > > I don't have access to this article, but from the author names, those > > > are people from the Simula laboratory doing SyFi. > > > > > > > > > > Definitely report back. We could put the best of what you find into > > > > Sage, if it isn't > > > > there already... > > > > > > Yep, let us know what you like the best. > > > > > > Writing a good FEM library is very hard. After trying fenics, syfi, > > > libmesh (I used that one for quite a long time), I ended up with > > > sfepy: > > > > > > http://code.google.com/p/sfepy/ > > > > > > that is Python + C, maybe not so nice documented for newcomers, but > > > very simple, fast, doing all I need and having the author 100km from > > > Prague, where I live. :) > > > > Just out of curiosity, do you think it would make sense to include > > sfepy in Sage? If so, would you (=Ondrej) be interested in being > > spkg maintainer for it? > > > > I think it's too early for that, but just to be sure, CCing Robert, > the main maintainer of sfepy. I think a good measure is when there are > enough > people using it (i.e. on the mailinglist, currently 11). > I would be very glad if sfepy would get into sage, but agree that it is probably too soon now. I am available at IRC channel #sfepy at Freenode (usually from 10 to 18 CE(S)T), so we can discuss there what requirements there are for a code to be included. 11 people on the list might look not so small, but me (and now Ondrej) are the only people actually writing the code, with one of my colleagues now starting too (even applying for a post-doc grant project). I see two principal areas that need to be addressed first: the documentation and the behaviour on failures/exceptions (the code works very well, but behaves as garbage-in/garbage-out and it is not easy for a casual user to recognize what in her/his input was wrong). No matter what the results of this discussion is, these must be done anyway, but every feedback is welcome! best regards, Robert --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Sage 2.11 for OS X 10.5 not working properly
On Mon, 07 Apr 2008 at 12:58AM -0700, Samuel Gaehwiler wrote: > Thank you very much, William. I'm looking forward to having a great > time with sage. As soon as I'm enough familiar with it I plan to write > an article about opensource math software in the "polykum" paper, > which is distributed to all researchers and students of my university, > the ETH Switzerland. Sadly, on the institutes I know (math, physics, > computer science and electronic engineering) most - if not all - math > software used is proprietary math software. This sounds like a great idea. There is also the idea of a "Sage Magazine" which is still in the planning stages...see http://wiki.sagemath.org/SageMagazine . Your article sounds like it could be a good fit for that. Dan -- --- Dan Drake <[EMAIL PROTECTED]> - KAIST Department of Mathematical Sciences --- http://math.kaist.ac.kr/~drake signature.asc Description: Digital signature
[sage-support] Re: Sage 2.11 for OS X 10.5 not working properly
On Mon, Apr 7, 2008 at 12:58 AM, Samuel Gaehwiler <[EMAIL PROTECTED]> wrote: > > > Could you try making a new clean user account and running > > sage -maxima > > from it? > > Thank you!! On a new user account sage and its maxima worked > beautifully. > > On my main account I found a folder called "Steuerfälle" generated by > a governement-software for calculating the taxes in Switzerland... I > changed that -> issue gone. Excellent! We're tracking this issue here: http://trac.sagemath.org/sage_trac/ticket/2841 I hope we can figure out how to fix Maxima so that it doesn't break like that even with funny files. > > Thank you very much, William. I'm looking forward to having a great > time with sage. > As soon as I'm enough familiar with it I plan to write an article > about opensource math software in the "polykum" paper, which is > distributed to all researchers and students of my university, the ETH > Switzerland. Sadly, on the institutes I know (math, physics, computer > science and electronic engineering) most - if not all - math software > used is proprietary math software. I really hope you'll write such an article. Definitely ask questions on sage-support if you have them. Writing such things, etc., is what we really need in order to grow the Sage user base. -- William --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Sage 2.11 for OS X 10.5 not working properly
> Could you try making a new clean user account and running > sage -maxima > from it? Thank you!! On a new user account sage and its maxima worked beautifully. On my main account I found a folder called "Steuerfälle" generated by a governement-software for calculating the taxes in Switzerland... I changed that -> issue gone. Thank you very much, William. I'm looking forward to having a great time with sage. As soon as I'm enough familiar with it I plan to write an article about opensource math software in the "polykum" paper, which is distributed to all researchers and students of my university, the ETH Switzerland. Sadly, on the institutes I know (math, physics, computer science and electronic engineering) most - if not all - math software used is proprietary math software. --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Sage 2.11 for OS X 10.5 not working properly
On Sun, Apr 6, 2008 at 11:58 PM, Samuel Gaehwiler <[EMAIL PROTECTED]> wrote: > > > Instead do > > ./sage -bdist some_name > > its available at http://people.ee.ethz.ch/~samuelg/sage/ > > > > 1. How much RAM? > > 2 GB (2x 1GB) DDR2 SDRAM 667 MHz > > > > > 2. What happens if you type > > > > ./sage -maxima > > *** - invalid byte #xCC in CHARSET:ASCII conversion > The following restarts are available: > ABORT :R1 ABORT > > ABORT :R2 ABORT > ABORT :R3 ABORT > Break 1 [4]> > > > > > 3. What happens if at the Sage prompt you type !maxima > > > > sage: !maxima > > *** - invalid byte #xCC in CHARSET:ASCII conversion > The following restarts are available: > ABORT :R1 ABORT > > ABORT :R2 ABORT > ABORT :R3 ABORT > Break 1 [4]> > > > > > 4. Do you have fink installed on your computer? > > no > > > > > 5. Are you using Macports? > > yes, MacPorts 1.600. > The files in my /opt/local/bin are listed in > http://people.ee.ethz.ch/~samuelg/sage/files_by_macports_in_opt_local_bin.txt > > > > > 6. Any weird language / internationalization issues? > > no. I have a Swiss German keyboard layout, but all previous > posted errors also occur when I use the U.S. keyboard setting. > Do you have any files anywhere in your filesystem that might not just use standard ascii characters in their names? Could you try making a new clean user account and running sage -maxima from it? I'm guessing a bug in Maxima is causing the problem. Maxima tries to read various directories on startup and behaves very stupidly in the presence of filenames that contain characters that confuse it. -- William --~--~-~--~~~---~--~~ To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-support URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
